With the rapid development of society, people have many security risks in their daily lives, for example, a stampede accident in a public place, a fall accident on an elevator, an old person falling alone at home but no one knows, etc. These fall accidents are likely to cause injuries, and even worse, loss of valuable lives and so on.
At present, in the field of monitoring falls at home and abroad for the elderly, patients and personnel engaged in dangerous work, most monitoring devices use wearable portable sensors, such as acceleration and angular velocity sensors, or simpler, help call buttons. However, most people are often reluctant to wear various sensor devices. After a person falls, the body cannot move or the brain loses consciousness. In this case, the help call button also fails. Another way to monitor falls is to use traditional camera monitoring to quickly identify a fall. However, the traditional camera is easy to cause misjudgment because it captures single data, and cannot identify people's movements such as bending over. Besides, because the sensor technology used is backward, the accuracy of determination is low, and the error rate is higher in an environment that is dim, at night or hot, etc.
Chinese patent document CN 104966380 discloses an alarm system capable of monitoring an accidental body fall, which comprises a background master unit, a camera unit, a sensing unit and an alarm unit; the camera unit and the sensing unit are responsible for capturing a body video image and a vibration signal; the background master unit is configured to perform framing processing on the body video image to determine whether a fall has occurred and whether the vibration signal exceeds a preset threshold; when it is determined that a fall has occurred and the vibration signal exceeds the preset threshold, an alarm signal is generated to control the alarm unit to sound a responding alarm; through the image identification technology, a fall is determined according to the height of center of gravity, the tilt angle and the effective area change of a person. This patent has the following disadvantages:
1. The accuracy of determining a fall according to the height of center of gravity, the tilt angle and the effective area change of a person is low, and it can be improved by the assistance of a high-sensitivity vibration sensor.
2. When it is determined that a fall has occurred, only a voice alarm can be sounded, and the external device cannot be controlled, with the purpose of rescue basically unachievable.